This invention relates to apparatus for the angioplasty of aneurysms, especially aneurysms of the aorta, for which the superior neck is short. The invention particularly relates to intraluminal prostheses for implementing of angioplasty of aneurysms, as well as balloons for the expansion of such prostheses.
In the current state of the art, a prosthesis of expandable cylindrical form is introduced at the level of the aneurysm. The endoprosthesis is formed by an expandable frame made, for example, of a mesh of metal wires, covered by a material that ensures impermeability, for example, made of DACRON (trade name) or polytetrafluoroethylene (PTFE). It ensures the continuity of blood flow between the vascular parts not injured by the aneurysm, and is supported upstream and downstream of the aneurysm on the interior wall of the neck.
The prostheses of the prior art are well adapted to situations in which the superior neck is straight and sufficiently long. The contact surface of the endoprosthesis with the healthy vascular parts is then sufficient to avoid leaks (see FIG. 1).
In contrast, the prostheses of the prior art are poorly adapted to situations in which the neck is short or oblique. In such cases, the connection between the endoprosthesis and the healthy vascular part is insufficient and leaks can occur, especially at the level of the superior neck. These defects have the tendency to worsen with time, because of possible sliding of the prosthesis or in the case of aggravation of the aneurysm. Thus, it would be highly advantageous to resolve this drawback of the prior art.
The invention concerns an angioplasty process for vessels injured by an aneurysm, including introducing at the level of the aneurysm an endoprosthesis formed by an expandable frame covered by an impermeable material and then implementing expansion of the endoprosthesis after positioning at the level of the aneurysm by means of a balloon catheter, characterized in that the endoprosthesis has a beveled end that is positioned at the level of the neck, with the front plane of the beveled end such that the front plane is essentially perpendicular to the aortic axis into which the endoprosthesis opens.
According to an embodiment intended for the repair of an iliac aneurysm, an iliac prosthesis is expanded by means of a balloon configured so as to exhibit asymmetrical inflation, advantageously by means of a balloon of general cylindrical form extended at one of its ends by a divergent part.
The invention also concerns an endoprosthesis formed by an expandable frame covered by an impermeable material for the angioplasty of a vessel injured by an aneurysm, characterized in that it has a cylindrical form on one end of which is beveled so as to be positioned at the level of a short and/or oblique neck in a manner such that the front plane of the beveled end is essentially perpendicular to the median axis of the inter-renal aorta.
Advantageously, the beveled end has a front plane forming with the median axis an angle comprised between about 15 and about 40 degrees.